Inhibitory effects and mechanisms of intestinal electrical stimulation on gastric tone, antral contractions, pyloric tone, and gastric emptying in dogs.
The aim of this study was to investigate the effects and mechanisms of intestinal electrical stimulation (IES) on gastric tone, antral and pyloric contractions, and gastric emptying in dogs. Female hound dogs were equipped with a duodenal or gastric cannula, and one pair of serosal electrodes was implanted in the small intestine. The study consisted of five different experiments. Liquid gastric emptying was assessed by collection of chyme from the duodenal cannula in a number of sessions with and without IES and with and without N-nitro-l-arginine (l-NNA). Postprandial antral and pyloric contractions were measured with and without IES and in the absence and presence of l-NNA or phentolamine by placement of a manometric catheter into the antrum and pylorus via the duodenal cannula. Gastric tone was assessed by measurement of gastric volume at a constant pressure. Gastric emptying was substantially and significantly delayed by IES or l-NNA compared with the control session. IES-induced delay of gastric emptying became normal with addition of l-NNA. IES reduced gastric tone, which was blocked by l-NNA. IES also inhibited antral contractions (frequency and amplitude), and this inhibitory effect was not blocked by l-NNA but was blocked by phentolamine. IES alone did not affect pyloric tone or resistance, but IES + l-NNA decreased pyloric tone. In conclusion, IES reduces gastric tone via the nitrergic pathway, inhibits antral contractions via the adrenergic pathway, does not affect pyloric tone, and delays liquid gastric emptying. IES-induced delay of gastric emptying is attributed to its inhibitory effects on gastric motility.
Zhao
Xiaotuan
X
Division of Gastroenterology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas 77555-0632, USA.
Yin
Jieyun
J
Chen
Jihong
J
Song
Gengqing
G
Wang
Lijie
L
Zhu
Hongbing
H
Brining
Doug
D
Chen
Jiande D Z
JD
D000320:Adrenergic Fibers / Q000502:physiology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D004285:Dogs; D004558:Electric Stimulation; D017615:Enteric Nervous System / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects; D007422:Intestines / Q000294:innervation*; D008365:Manometry; D009119:Muscle Contraction / Q000187:drug effects; D009433:Neural Inhibition; D026602:Nitrergic Neurons / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D019518:Postprandial Period; D011312:Pressure; D011706:Pyloric Antrum / Q000187:drug effects / Q000294:innervation*; D011708:Pylorus / Q000294:innervation*; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists; D004791:Enzyme Inhibitors; D019335:Nitroarginine; D019001:Nitric Oxide Synthase; D010646:Phentolamine